Plasma Processing Electromagnet Group for Ion Control
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Solution Overview
Problem
In inductively coupled plasma processing apparatuses, there is a lack of effective control over the ratio of ions and radicals reaching the workpiece, which affects the efficiency and precision of plasma processing operations such as etching and film formation.
Innovation Solution
The apparatus includes an electromagnet group disposed along the outer circumference of the processing container, which forms a magnetic field that can be switched between a horizontal and a cusp configuration, and the magnetic field strength can be controlled to optimize the ratio of ions and radicals reaching the workpiece by adjusting the magnetic poles and current flow, allowing for precise control during different plasma processing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a planar antenna is used to introduce an induced electric field into the processing container, then plasma is generated and processing can be performed, but the ratio of ions and radicals reaching the workpiece cannot be effectively controlled
Solution Approach 1:
The electromagnet system is divided into multiple independent electromagnets (first and second electromagnets) positioned at different locations around the processing container. Each electromagnet can be controlled independently to create different magnetic field configurations, enabling precise control over ion and radical distribution without requiring a complete system redesign.
Solution Approach 2:
The magnetic field is applied locally around the processing container rather than uniformly throughout the entire system. By positioning electromagnets at specific locations and controlling their individual fields, the system creates localized magnetic field regions that selectively influence ion and radical behavior near the workpiece while maintaining overall system simplicity.
2Manufacturing precision
If the magnetic field strength is increased to suppress ions, then ion control improves, but energy consumption increases
Solution Approach 1:
Instead of applying a strong magnetic field uniformly throughout the entire processing container, the system applies magnetic field strength that is sufficient only in the critical regions near the workpiece where ion suppression is needed. The electromagnets are positioned and controlled to create partial magnetic field coverage, reducing overall energy consumption while achieving the required ion control effect.
Solution Approach 2:
The system dynamically adjusts magnetic field strength parameters based on processing requirements. By changing the current applied to individual electromagnets, the magnetic field intensity can be optimized for each specific processing step, balancing ion suppression effectiveness with energy efficiency rather than maintaining constant high field strength.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables precise control over the ratio of ions and radicals reaching the workpiece, enhancing the efficiency and precision of plasma processing operations by suppressing ions where necessary and maintaining optimal radical levels, thus improving the outcomes of etching and film formation processes.
Implementation Method 1
an electromagnet group disposed along an outer circumference of the processing container and configured to form a magnetic field for moving ions in plasma based on the induced electric field along the facing surface of the dielectric member
Implementation Method 2
a planar antenna provided on a surface of the dielectric member opposite to the facing surface and configured to introduce an induced electric field for plasma excitation into the processing container via the dielectric member
Implementation Method 3
a gas in the processing container is dissociated by the induced electric field introduced into the processing container from the antenna, so that plasma is generated. The plasma contains active species such as, for example, ions and radicals
Data Source
AI summary
An apparatus includes a plasma processing container; a workpiece placement table disposed in the plasma processing container; a dielectric member having a facing surface that faces the workpiece placement table; an antenna provided on a surface of the dielectric member opposite to the facing surface and configured to introduce an induced electric field for plasma excitation into the plasma processing container via the dielectric member; an electromagnet group disposed along an outer circumference of the plasma processing container and configured to form a magnetic field in the plasma processing container; and a controller configured to control magnitudes of electric currents flowing through respective electromagnets of the electromagnet group differently from each other, to generate a magnetic gradient along a circumferential direction in the magnetic field that exists only in an outer circumferential space in the plasma processing container.